If *C1()* and *C2()* are the letter counts for the two subalphabets, then if 
the *A* of the first subalphabet is shifted to the letter *#* of the second 
subalphabet, we calculate

<br>*C1(A)\*C2(#)* + *C1(B)\*C2(#)* + ...

<br>for *#* = A, B, ...

<br>The largest value is indicated in the display.
